SAN FRANCISCO

In a postseason full of twists and turns, the San Francisco Giants are headed back to the World Series after a big comeback against the defending champs.

Hunter Pence got the Giants going with a weird double, Matt Cain pitched his second clincher of October and San Francisco closed out Game 7 of the NL championship series in a driving rainstorm, routing the St. Louis Cardinals 9-0 Monday night.

San Francisco won its record-tying sixth elimination game of the postseason, completing a lopsided rally from a 3-1 deficit.

“These guys never quit,” Manager Bruce Bochy said. “They just kept believing and they got it done.”

The Giants, who won it all in 2010, will host Justin Verlander, Miguel Cabrera and the Detroit Tigers in Game 1 on Wednesday night.

Series MVP Marco Scutaro produced his sixth multihit game of the series and matched an LCS record with 14 hits and Pablo Sandoval drove in a run for his fifth straight game.

After falling behind 3-1 in the series at Busch Stadium, the Giants outscored the wildcard Cardinals 20-1 over the final three games behind stellar starting pitching from Barry Zito, Ryan Vogelsong and Cain.

They also benefited from some strange bounces.

On Pence’s double that highlighted a five-run third, his bat broke at the label on impact, then the broken barrel hit the ball twice more. That put a rolling, slicing spin on the ball and caused it to change directions — leaving shortstop Pete Kozma little chance to make the play. Kozma broke to his right, figuring that’s where the ball would go, but it instead curved to left-center.

Injured closer Brian Wilson, with that out-of-control bushy black beard, danced in the dugout and fans in the sellout crowd of 43,056 kept twirling their orange rally towels even through rain in the late innings — a downright downpour when Sergio Romo retired Matt Holliday on a popup to Scutaro to end it.

“This rain never felt so good,” Scutaro said.

Romo embraced catcher Buster Posey as fireworks went off over McCovey Cove beyond right field.

The NL West champion Giants won their first postseason clincher at home since the 2002 NLCS, also against the Cardinals.

NOTES: The Giants snapped an 0-5 skid in deciding Game 7s. … The Tigers and Giants will meet for the first time in the postseason. … Beltran stole his third base of the postseason in the first, making him 11 for 11 in his postseason career — most in a postseason without being caught. … This was the first NLCS Game 7 since 2006, when the Cardinals beat the Mets and Beltran struck out looking against Adam Wainwright with the bases loaded to end it. … The Giants are 11- 17 in franchise history facing elimination.